package com.qinker.oa.utils;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

public class SignUtil {

    private static final String TOKEN = "lorywechat";

    public static boolean checkSignature(String signature, String timestamp, String nonce){
        String[] strs = new String[]{TOKEN, timestamp, nonce};
        Arrays.sort(strs);
        StringBuilder builder = new StringBuilder();
        for (int i = 0; i < strs.length; i++) {
            builder.append(strs[i]);
        }
        MessageDigest md = null;
        String tmpStr = null;
        try {
            md = MessageDigest.getInstance("SHA-1");
            byte[] disgest = md.digest(builder.toString().getBytes());
            tmpStr = byteToStr(disgest);
        }catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        builder = null;
        return tmpStr != null && tmpStr.equals(signature.toUpperCase());
    }

    private static String byteToStr(byte[] byteArray) {
        String strDigest = "";
        for (int i = 0; i < byteArray.length; i++) {
            strDigest += byteToHexStr(byteArray[i]);
        }
        return strDigest;
    }

    private static String byteToHexStr(byte mByte) {
        char[] Digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
        char[] tempArr = new char[2];
        tempArr[0] = Digit[(mByte >>> 4) & 0X0F];
        tempArr[1] = Digit[mByte & 0X0F];
        String s = new String(tempArr);
        return s;
    }
}
